In the related art, an intake device including a valve body disposed in an intake port is known (for example, refer to Japanese Patent No. 5255922 (Reference 1)).
In Reference 1 described above, a variable intake device including an intake control valve (valve body) disposed in the intake port is disclosed. The intake control valve includes a valve main body made of a resin material and a seal lip which is provided on an outer circumferential edge surface of the valve main body and is made of a rubber material.
In the variable intake device described in Reference 1, there is a case where the seal lip made of a rubber material is provided on the outer circumferential edge surface of the valve main body by an injection molding. In this case, as a seal lip forming material flows into a seal lip molding die in a state where the valve main body is disposed in a seal lip molding die, the seal lip is formed on the outer circumferential edge surface of the valve main body. In the injection molding, there is a case where a void is generated between the seal lip molding die and the valve main body in a case where the seal lip molding die and the valve main body do not tightly adhere to each other due to an unevenness of dimension of the valve main body. In this case, via the void generated between the seal lip molding die and the valve main body, it is considered that the seal lip forming material flows into a surface region on an inner side of the valve main body, the flowing-in part is generated as a flash, strength of the seal lip deteriorates, or dimension accuracy of the seal lip deteriorates. In addition, when the seal lip forming material flows into the surface region on the inner side of the valve main body, it is considered that a pressure of the seal lip forming material is applied to the valve main body, and deformation is generated in the valve main body. Therefore, when forming a seal portion, due to flowing of the seal lip forming material into the surface region on the inner side of the valve main body, it is considered that there is a problem that a manufacturing defect is generated in the intake control valve (valve body).
Thus, a need exists for an intake device which is not susceptible to the drawback mentioned above.